Unthinkably favourable

'It's an ill wind that blows no-one any good" is a common adage. Less common but equally valid is that "It's a benevolent breeze that blows no-one any harm." Stress tests around oil prices inevitably focus on a major increase, but a significant fall in oil prices would have certain negative consequences. A major increase is certainly the type of price shock that seems most likely.

Potential disruptions of supply are easy to imagine. They could arise due to political instability in the Middle East